Automatic tuning mechanism for radio receivers



Sept. 30, 1941.- M. SAMBURG v2,257,531

AUTOMATIC TUNING MECHANISM FOR RADIO RECEIVERS Filed Oct. 4, 1939 3 Sheets-Sheet 1 .III I! -III .IH II"! II" I N V EN TOR. MHz/e ICE S/I/VBI/EG TTORNEYS.

.. a I MILE! I Sept. 30, 1941. M. SAMBURG 2,257,537

I AUTOMATIC TUNING MECHANISM FOR RADIO REQEI YERS Fi led Oct. 4, 1959 s Sheets-Sheet 2 1 4 LL INVENTOR. A7402 /c E Sta/7502c;

MUM 3mm.

Sept. 30, 1941. M. SAMBURG AUTOMATIC TUNING MECHANISM FOR RADIO RECEIVERS Filed Oct. 4, 1939 3-Sheets-Sheet 3 Pea/0 Cw l INVENTOR.

TUNING UNI T ATTO EYS.

Patented Sept. 30, 1941 UNITED STATES PATENT OFFICE AUTOMATIC TUNING MECHANISM FOR RADIO RECEIVERS 3 Claims.

This invention relates to time controlled mechanism and more particularly to apparatus for automatically tuning a radi receiving set throughout a predetermined period of time. The apparatus, in its preferred form, is constituted of a separate structure, the constituent elements of which may be embodied in a casing of comparatively small dimensions from which extend two connections suitable for plugging into two cooperating receptacles in the radio receiving set. The tuning apparatus, of course, may be included in the construction of the receiving set.

The principal object of the invention is to provide an attachment whereby the automatic tuning of a standard radio set to a particular broadcasting station at any particular time, or to a plurality of stations in any predetermined order at periodic intervals, may be accomplished by the pro-adjustment of certain elements of the mech anism. My invention further contemplates, and I have provided for, the selection f either a continuous or a discontinuous program over a specific interval of time, the automatic tuning to the desired station or stations being accomplished only at such periods as have been previously determined.

A still further object of my invention is the provision of an adjunct or attachment to a standard radio set which eliminates the necessity of any adjustment whatsoever during the entire period of time for which the apparatus has been originally designed or its use contemplated. and for which the desired program has been selected. This period may be as high as twenty-four hours although obviously, a shorter period, for instance twelve hours, as in the particular embodiment of my invention selected for illustration, is ordinarily suflicient.

My automatic tuning mechanism depends upon its operation not upon a complicated series of electric circuits in which contacts are successively made in a large number of separate electric circuits connected to points in the controlling clock mechanism, but upon a mechanical operation of certain elements of the apparatus. Thus. while the electric connections between the tuning mechanism and the radio set are necessarily utilized, they are of the simplest possible nature involving no more than the connection of certain conductors in the radio receiving set as now found upon the market, to corresponding conductors to the tuning mechanism.

My automatic tuning mechanism accomplishes not only the switching necessary to bring the set into the proper tuned condition for the particular station desired at any definite hour or sub-division thereof, but is efiective also to turn the radio set on and off for any predeterminable period of time.

Other specific objects of my invention are the provision of mechanically operated elements controlled by the simple adjustment of the station selective mechanism and the provision of a substantially fool-proof and operable combination of elements which may be embodied in a separate casing that may be positioned remote from the receiving set itself so that even if a change is desired in the predetermined sequence of stations v to which the receiving set was originally set, such change in such predetermined sequence may ,tion, the tuning of the set to any particular station being accomplished by the pressure inwardly upon a panel, of particular station selective buttons.

In accordance with my invention, the tuning mechanism need not be used at all times, its design being such that the tuning of the radio set t any other station than one of those for which a particular button is provided, is possible. Furthermore, my apparatus is so constructed that its operation may be completely dispensed with, the tuning from time to time of the receiving set, being capable of accomplishment in the ordinary manner as if the tuning mechanism were not attached thereto.

Broadly speaking, my invention contemplates the provision of an automatic tuning unit and appurtenant mechanism which comprises a clock mechanism controlling the periodic tuning of a standard radio receiving apparatus at intervals,

- for instance of 15 minutes for an extended period,

for instance, of 12 hours. Attached to the clock mechanism is a cam which may be set to begin operation of the tuning unit at the beginning of any 15 minuteperiod. The tuning mechanism includes as an element thereof, a disc provided with a series of perforations, the perforations being disposed in the surface of the disc extending radialiy thereof and in a number equivalent to the number of stations to which the radio may be automatically tuned. Upon the disc are provided a plurality of pins one of which may be inserted, When the tuning device is being set, into one of each series of radial apertures in the disc. As the cam of the clock mechanism rotates, it causes, by an intervening arm, operative upon a ratchet wheel secured to the disc to rotate the disc and to cause successive pins extending through the apertures therein to abut a corresponding pivoted lever causing the same to turn to a slight extent about its pivot, the extent of such turning being sufiicient to cause engagement of three contact points carried thereby with the three corresponding contact points of the conventional tuning mechanism of a standard type of radio receiver having buttons for selective tuning to individual stations. Thus, as a particular station is tuned in by the abutment of one pin in any radial series of apertures in the disc against the corresponding pivoted lever, the particular station controlled by such pin and aperture in the series and therefore by the pivoted lever, is brought to tuned position. If the same station is to be retained in tuned position for another period of 15 minutes, a pin in the same circumferential line of apertures will again abut the same station lever and without any interruption of the program, continue the operation of the set at the same station. My novel tuning mechanism includes apparatus to turn the radio set on or off at any predetermined time in the cycle for which it has been designed. Thus, the clock mechanism and its circuit is so interconnected with the radio circuit, that it is effective to turn the set on, and yet, by the provision of a second switch, the set is at all times in operative condition for manual positioning of the station selective buttons whether the clock switch is on or off.

A particular embodiment of my invention as applied to a standard radio receiving set now to be found on the market is illustrated in the accompanying drawings, in which Fig. 1 is a perspective view of the tuning mechanism and my apparatus as encased in a box having a cover which may be opened for adjustment and selective positioning of the automatic tuning elements and of the clock controlling the same; Fig. 2 is a plan view of the tuning mechanism, parts of the dial attached to the clock and of the disc by means of which the predetermined automatic tuning of the radio set is effected, being broken away; Fig. 3 is a front view of the automatic tuning mechanism without the housing, the same being removed; Fig. 4 is a vertical section through the tuning mechanism along the lines 44 of Fig. 3; Fig. 5 is a section along the line 55 of Fig. 4; Fig. 6 is a plan view of the mechanism along line 66 of Fig. 3; Fig. '7 is a section through the clock controlled mechanism along line 1-! of Fig. 2; Fig. 8 is an enlarged detail of the mechanically operated switching elements; Fig. 9 is a side view thereof; Fig. 10 is a wiring diagram of the radio proper electric circuit; and Fig. 11 is an external wiring diagram of the circuits leading to and from the tuning unit.

Referring more particularly to the drawings, in which similar reference characters identify similar parts in the several views; I2 is the casing for the automatic tuning unit and selective mechanism, having a cover l3 and from which casing extend cables l4 and I5 for connection to the proper receptacles in the radio receiving set. Connected to the ends of the cables are the plugs l6 and IT, the former constituting the connection from the clock and power line of the tuning mechanism to the radio and the latter the conmotion from the master switch of the tuning mechanism, to the receiving set.

Upon two upwardly extending standards 20 and 2| are supported a plurality (six in the particular embodiment illustrated) of levers 22, pivoted intermediate their ends upon pins 23 passing therethrough. The group of levers passes through an aperture in a plate 24 extending throughout the upper portion of the tuning mechanism approximately at the center of which is secured a shaft 25 carrying the hub 26 of a ratchet wheel 21 below which is positioned the heel portion 28 of a lever arm 29 carrying at its end the block supported elbow 30, the free end of which is adapted to ride upon the surface of the cam of the clock mechanism hereinafter to be described.

The ratchet 21 is mounted for progressive rotation, notch by notch, about the shaft 25, by means of a pawl 3| pivoted about the pin 32 extending from the surface of the lever arm 29 adjacent the periphery of the ratchet wheel. The pawl 3| is secured at one end thereof to spring 33 which at its other end is anchored upon a pin 34, extending from the surface of the lever arm 29. Upon the same pin is anchored one end of a spring 35, anchored at its other end upon a pin 36 extending from the plate l8. Retrograde movement of the ratchet wheel is prevented by pawl 3'! controlled by spring 38 likewise anchored upon a pin 39 extended from the plate 24.

Secured by a screw 40 to the hub 26 is a disc 4| having a plurality of concentrically arranged series of apertures 42 which apertures are, in the particular embodiment illustrated six in number extending radially of the disc 4|, a total number of apertures 42 provided in the disc being dependent upon the number of stations which are to be selectively tuned and the particular number of hours, for which the disc has been designed in order to provide for the automatic tuning of the radio set over a predetermined period of time, in the particular instance illustrated, this period of time being twelve hours. Since there are six radially aligned apertures, one for each station for the automatic tuning to which the tuning unit has been designed and there are twelve hour segments upon the disc, with a set of six radial apertures for each 15 sub-divisions of an hour, there are altogether 288 of the apertures 42 provided in the disc.

Two concentric series of somewhat larger apertures 43 are provided upon the disc interiorly of the innermost line of apertures 4|, such larger apertures 43, of which there may be a number corresponding to the number of radial series of apertures 4|, are provided for the purpose of acting as storage apertures for the pins 44 having knurled heads 45 of larger diameter than the body of the pins. The portion of the pins 44 intermediate the head and the body is preferably threaded as at 46 to cooperate with internal threading in the apertures 43 of the disc. Upon the plate 24 there is provided a pointed index 41. The disc 4| is retained in position also by a round plate 48 secured to the shaft 25 by screw 49.

Coming now to the clock mechanism, such mechanism is likewise secured to the plate 24, from which the clock 50 depends by securement thereof to the plate by screws 5|. The clock shaft 52, as shown in Fig. '7, is topped by a knurled knob 53 retained on the shaft by a nut 54, the knob being integral with the dial 55 marked on its top surface with the digits indicating minute intervals. Upon the plate 24 is a pointed index 56 adjacent the periphery of the dial. Below the dial 55, and secured thereto by key 51, is a cam 58 to which in turn is secured by screws 59 a ratchet wheel, retrograde movement of which is prevented by a spring controlled pawl 6|. The dial 55, cam 58, and ratchet wheel are all mounted upon disc 62. The rotation of the shaft 52 of the clock mechanism will thus cause rotation of the cam 58 the setting of the dial 55 to the beginning of a fifteen minute period being accomplished by means of the knurled knob 53. The cam is thus rotatable in one direction but not in the other.

Coming now to a description of the mechanical tuning mechanism as eiiected by means of the levers 22, extending from each of such levers is a contact plate 65 having at its free end three contacts 86, 61 and 68. When one of the levers 22 is pivoted about its pivot point 23 by the abutment of pin 44 against the upper extremity thereof, the plate 65 of the particular lever is caused to move sidewise (Fig. 8) so as to bring its contact 66, E1 and 68 into cooperative engagement with the contacts 69, 10 and 1| respectively of the standard tuning unit of the radio. It will be noted that the contact plates of the levers 22 are alternately staggered, three in one line, and three in another, in order to have the mechanism as compact as possible.

The sidewise movement of the contact plate 65 causes a corresponding movement of the angular plate 12 against the tension of the spring I3, causing abutment of the pin 14 depending from the plate 12 with the pin 15. The pin 15 extends upwardly from a pivoted arm 16 mounted upon. the bracket 11, the contact 18 being secured to the lower portion of the pivoted arm 16. Upon abutment of the pin 14 against the pin 15, thereby moving the latter backwardly, the contact '18 is brought forward so as to push the contact 19 inwardly. The contact 19 operates the switch 80 in the usual manner of the standard radio receiving apparatus.

Referring particularly to Fig. 6, it will be seen that no change has been efiected in attaching my automatic tuning mechanism to the standard radio receiving set of the type illustrated, the contacts brought into operation by the pivoting of the levers 22 by the pins 44 extending through the apertures in the disc 4| being effective to complete the electrical circuit through the same group of contacts, each group being three in number, operated by pushing in the buttons of the radio receiving set tuning unit. Thus, in order to attach my automatic tuning mechanism to a standard radio receiving set, no changes in the circuit of such standard radio receiving set need be made. This is also evident from the wiring diagram, Fig. 11, in which the three contacts of each pivoted lever are shown as electrically connected to the three conductors of each of the push buttons of the standard set tuning unit.

The operation of the apparatus is as follows:

When my novel tuning mechanism is for the first time connected to a particular radio receiving set, and only at such first time, it is necessary to synchronize the clock and appurtenant structure, including the cam, to the exact time the connection is made. Thus, when the tuning mechanism is connected to the radio receiving set, before the mechanism can operate to automatically tune the radio to preselected and predetermined stations upon that particular radio set, the following operation must be carried out:

The operator determines the exact time at which the interconnection is taking place and will set the clock mechanism so that the clock operates in synchronism with such exact time. This is accomplished by setting the disc 4|, by rotating the same to the nearest hour and of an hour, for instance, in the event that the mechanism is being adjusted at 6:47, by rotating the disc until the pointed marker 41, points at the series of radial apertures therein opposite the third series after the figure 6 upon the disc. This will indicate that the disc 4| is set at 45 minutes past six. The dial of the clock mechanism is then turned by means of the knob 53 until the pointer 56 is opposite the number 2, the clock control mechanism being thus set by two minutes past the zero of the 15 minute period for which it is designed. This is the only operation necessary in order to synchronize the clock with the actual time.

If the operator is then desirous of having a particular station, identified by the outermost concentric series of apertures upon the disc 4|, one of the pins 44 is removed by the operator from its storage aperture 43 and placed into the outermost aperture of the radial series opposite the pointer 41. If at seven oclock a different station, for instance one identified by a diirerent line of concentric apertures, is desired by the operator to be tuned in automatically, a second pin 44 is inserted by him into the aperture, corresponding to such station in the radial series opposite the figure 7. If the same station is desired to be tuned in at 7:15, still another of the pins 44 is placed in the same concentric line of apertures 42, but in the next succeeding radial series of apertures, namely those opposite 7:15 oclock. If, for the next fifteen minute period, the radio receiving set is desired to be shut on", no pin is placed in any of the radial series of apertures. If the radio set is desired to be again turned on, for instance, at eight ocloclr but at a still different station, for instance that corresponding to the innermost series of concentric apertures, a pin 44 is placed into the innermost of the concentric apertures opposite the figure 8 upon the disc. In this manner, an number of stations in any predetermined order may be selected at one time and the automatic tuning mechanism will operate to tune in the particular station at a particular predetermined time, or if no pin is inserted into any particular aperture opposite a particular 15 minute period, the radio will be automatically turned off.

In effecting this automatic tuning, as the clock shaft 52 rotates, it will cause the rotation of the cam 58, retrograde movement thereof being prevented by the ratchet wheel and pawl 6!, the elbow 30 of th lever arm 29 riding upon the periphery of the cam until it enters the low dwell of the cam by the action of the spring 35, thereby rotating the ratchet 2'! one notch by means of the pawl 3! and rotating th disc ii through a segment equivalent to a fifteen minute period. As such rotation of the disc 45 takes place, the pin 44 extending therethrough will abut the corresponding lever 22, causing it to pivot about its pivot point 23 and to move the contact plate thereof to bring the contacts 65, t1 and 68 into engagement with the contacts 69, "H3 and H of the conventional tuning unit, thereby causing the operation of such tuning unit in the conventional manner and bringing the condensers or the radio set into their position in which they are tuned to a particular station.

At successive 15 minute periods this operation is repeated with a pin 44 activating one of the six levers 22 and bringing the particular station into tuned position, the station being tuned in, being that which is controlled by the particular pivoted lever abutted by the pin 44.

It is to be noted that if for two or more successive 15 minute periods the same station is to remain tuned in, there will be no interruption in the broadcast receiving from such station because as soon as one pin has passed beyond the point at which it holds the corresponding lever 22 in its pivoted position, the next succeeding pin comes into immediate operation to again bring th lever 22 into its pivoted position.

As soon as one of the levers 22 assumes its pivoted position, the pin 14 extending from the lower extremity of the arm 12 will abut the pin 15 of the pivoted arm 16, so as to cause the contact 18 thereof to push inwardly the switch elements 19, causing the switch 80 to operate and connect the radio receiving apparatus to the power line. When the lever 22 re-assumes its upright position, the radio is automatically turned on.

It will be understood by those skilled in the art that the operation of my automatic tuning mechanism may be dispensed with at any time that the operator desires manually to tune the receiver to any particular station. The standard radio set with a tuning unit is provided with two knobs, one for operation of the tuning unit, and the other for manual operation. As my automatic tuning mechanism is connected to the tuning unit, manual tuning of the receiver, in conventional manner, may be carried out upon turning the knob disconnecting the tuning unit, i. e. the knob usually marked Manual.

While I have described a specific embodiment of my invention, it is obvious that various changes therein, particularly in the arrangement, disposition, and structural character of the several parts thereof, may be made, without departing from my invention.

I claim:

1. In a control system of the class which includes a receiver and a selecting unit having selecting elements constructed and arranged to establish a receiving relation between said receiver and each of a plurality of stations selectively; mechanism constructed and arranged to determine the time of operation of said selecting unit by operating said elements to establish said relation with individual, preselected stations throughout a predetermined period of time at any subdivision of such period, or to a plurality of stations in any predetermined order at periodic intervals, said mechanism comprising a clock, a dial operatively connected thereto, a cam rotatable with said clock, a disc having a plurality of perforations disposed radially of the disc and corresponding to preselected stations with which said receiver is to be made effective selectively, such series of radially disposed perforations being arranged concentrically of the disc for a predetermined range of time, a plurality of pins detachably insertable into said apertures in successive series of the concentric apertures, a lever arm secured to the shaft of said disc to rotate said disc at periodic predetermined intervals, and a plurality of pivoted levers corresponding in number to the radially disposed apertures in said disc, said pivoted levers being adapted to be abutted by said pins, and coacting lever members carrying contact points adapted, upon pivoting of said levers, to contact conductors leading to said selecting unit, said pivoted last named lever members each having a pin near the free end thereof adapted to cause the operation of a switch to turn the receiver on and off.

2. In an automatic tuning device which includes a radio receiver and a tuning unit having tuning elements constructed and arranged to establish a receiving relation between said receiver and each of a plurality of stations selectively; mechanism constructed and arranged to determine the time of operation of said tuning unit by operating said elements to establish said receiving relation with individual preselected stations throughout a predetermined period of time at any subdivision of said period, or to a plurality of stations in any predetermined order at periodic intervals, said mechanism comprising a clock, a dial connected operatively thereto, a cam rotatable with said clock, a disc having a plurality of perforations disposed radially of the disc and corresponding to preselected stations to which the radio receiver is to be tuned, each series of radially disposed perforations being arranged concentrically of the face of said disc for a predetermined range of time, a plurality of pins detachably insertable into said apertures in successive series thereof, a lever arm connected to the shaft of said disc to rotate said disc at periodic predetermined intervals and a plurality of pivoted levers corresponding in number to the radially disposed apertures in said disc, said pivoted levers being adapted to be abutted by said pins, and coacting lever members carrying contact points adapted, when said coacting members are moved by pivoting of said levers, to contact conductors leading to said tuning unit, said coacting members each being provided with means, near its free end, adapted to cause the operation of a switch to turn said radio receiver on and off.

3. In an automatic tuning device which includes a radio receiver and a tuning unit having tuning elements constructed and arranged to establish a receiving relation between said receivers and each of a plurality of stations selectively; mechanism constructed and arranged to determine the time of operation of said tuning unit by operating said elements to establish said receiving relation with individual preselected stations throughout a predetermined period of time at any subdivision of such period, or to a plurality of stations in any predetermined order at periodic intervals, said mechanism comprising a clock, a dial connected operatively thereto, a cam rotatable with said clock, a disc having a plurality of perforations disposed radially of the disc and corresponding to preselected stations to which the radio receiver is to be tuned, such series of radially disposed perforations being arranged concentrically of the face of said disc for a predetermined range of time, a plurality of pins detachably insertable interchangeably into successive series of the concentric apertures, means connected with said disc to rotate said disc at periodic predetermined intervals, and a plurality of pivoted levers corresponding in number to the radially disposed apertures in said disc, said pivoted levers being adapted to be abutted by said pins, and coacting slide members carrying contact points adapted, when said slides are moved by pivoting or" said levers, to contact conductors leading to said tuning unit, said slide members being each provided with means, near its free end, to cause the operation of a switch to turn the radio receiving set on and 01T.

MAURICE SAMBURG. 

